1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device for processing a substrate, and a substrate processing apparatus.
2. Description of the Related Art
As one of processes for manufacturing a semiconductor device such as a dynamic random access memory (DRAM), a process of forming a third metal oxide film containing first and second metal elements is performed by alternately repeating a plurality of times a process of forming a first metal oxide film containing the first metal element on a substrate such as a silicon wafer and a process of forming a second metal oxide film containing the second metal element.
The composition ratio of the first and second metal elements in the third metal oxide film is determined by the thickness of the first metal oxide film and the thickness of the second metal oxide film formed in each process. The composition ratio in the thickness direction of the third metal oxide film becomes uniform as the first and second metal elements reciprocally diffuse between the alternately stacked first and second metal oxide films.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2004-214602
However, at a certain composition ratio of the third metal oxide film, the first and second metal elements may not reciprocally diffuse between the first and second metal oxide films to sufficient degree. In this case, the composition ratio of the third metal oxide film may not be uniform in the thickness direction of the third metal oxide film.